2018-12-16
Looking back at the post history, and it appears that I am quite the Chatty Cathy this month. Lots of progress being made. First order of business: I screwed up the naming in a bunch of places. Instead of referring to the expansion board as VSPB (Vic’s Serial and Power Board) I referred to it as VPSB (Vic’s Power Serial Board). Well it’s easier to rename it than to change all of the references, so Read more…
2018-12-13
The VSPB (Vic’s Serial and Power Board) has been delivered from Elecrow, populated, and reflowed in my reflow toaster. Other than mixing up TSSOP and SSOP footprints (that’s a whole different post) everything I have tested so far is functional. Gratuitous picture: I am super digging the white solder mask.
2018-12-09
Because I can not leave well enough alone, I decided to add insulation to my reflow toaster. Bellow are the results of the “learn mode” of the reflow controller. Basically what the controller does is ramp the heaters up and down and measure the temperature change vs time vs relay on-time. For more details go here: http://www.whizoo.com/intelligent . The hope was that as more insulation was added the oven score would improve. This is Read more…
2018-12-06
Well well well. Looksie at what we have here. You can tell I am a professional photographer by the chic ‘old notebook’ background. All parts are in. The reflow toaster is operational. I think we’re going to have a functional board this weekend.
2018-12-04
So anyone that has had boards manufactured by Elecrow (https://www.elecrow.com/) knows what that picture means – the stuff is in the mail. For those that do not partake in hobbies that involve custom fabrication by Chinese firms, every time Elecrow completes an order, they email you a picture of it before sending it out. I am exited. This is the first four layer board I have done and this is the first time I have Read more…
2018-09-17
With the gate driver IC and the MOSFET in possession, it was time to experiment. Below is a potato-cam(tm) pic of the layout. Fun fact: initially I forgot to hookup the ground on the gate driver chip and spend 30 minutes scratching my head. It’s hard being dumb sometimes. So what we’re seeing on the right hand side is the 8 pin gate driver and below it to the right is the MOSFET. I am Read more…
2018-09-13
I have been playing with the PIC24 which will be the basis for the serial and power board. Side track: need a catchier name for the serial and power board. SPB? S and PB? SaPB? VSPB? Vic’s SPB? Executive decision made: VSPB – Vic’s Serial and Power Board. Boom. Done. I have been playing with the PIC24 which will be the basis for the VSPB. I don’t know if I like Microchip PICs because they’re Read more…
2018-09-08
Onto the Beaglebone shield. The goal of this project is to produce an expansion board for the Beaglebone that breaks out the RS232 ports, provides power for the Beaglebone, and controls the power to the IO boards. There are several reasons for wanting to control the power to the IO boards: The Beaglebone can not have any voltage applied to its inputs until a specific stage of the boot process. While we could achieve above Read more…
2018-09-07
So I have been playing with the board and I can not find any show-stopper problems. I have tested every feature and there is not a single problem that can’t be software calibrated or hand-waved away. No in no way am I implying that it is perfect. Far from it. But it’s good enough to do what I designed it to do. Could some things have been done differently? Better? More efficient? Sure, of course. Read more…
2018-09-03
I know I’ve said it before, but I will go ahead and say it again: the end is in sight. In the last few days I’ve addressed the last few remaining issues: 1. Persistent offset on analog input #8 (ICD4) Turned out to be an input voltage offset issue. See here for more details. 2. ADC input weirdness on analog inputs 4-8 (ICD inputs) The short version is that the op amp output is at Read more…